Transformer chamber for a wind turbine, wind turbine structure component, wind turbine, and method for assembling a wind turbine

ABSTRACT

A transformer chamber for a wind turbine is described. The transformer chamber includes a liquid-tight tank for receiving a liquid-filled, in particular oil-filled, transformer, a wind turbine structure component includes a component bedframe adapted for receiving such a transformer chamber and a wind turbine includes such a transformer chamber and such a wind turbine structure component. Furthermore, a method for assembling a wind turbine is described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority of European Patent Office applicationNo. 11179874.0 EP filed Sep. 2, 2011. All of the applications areincorporated by reference herein in their entirety.

FIELD OF INVENTION

The present disclosure relates to the field of wind turbines. Inparticular, the disclosure relates to a transformer chamber, a windturbine structure component, a wind turbine, and a method for assemblinga wind turbine.

BACKGROUND OF INVENTION

Wind turbines becoming more and more popular for ecological powergeneration.

Power generated by wind turbines has to be transformed to betransportable via high voltage transmission lines to the consumers.

Liquid leaking from a liquid-filed transformer in case of a transformerfailure may harm, in particular electrical and controlling, componentsnear the liquid-filed transformer.

SUMMARY OF INVENTION

There may be a need for a transformer chamber, a wind turbine structurecomponent, a wind turbine, and a method for manufacturing a wind turbinereducing the risk associated with leaking liquid.

This need may be met by the subject matter according to the independentclaims Embodiments are described by the dependent claims.

According to a first aspect, there is provided a transformer chamber fora wind turbine comprising a liquid-tight tank for receiving aliquid-filled, in particular oil-filled, transformer. This aspect isbased on the idea that a second shell may limit the effect oftransformer failures, as liquid originating from the transformer may bekept contained within the liquid-tight tank.

Liquid-filled transformers are used as they may allow for better heatdissipation from coils and transformer sheets during operation of thetransformer. In particular, insulating liquids may be used forliquid-filled transformers. These insulating liquids may help to avoidcorona formation and arcing within the transformer.

Some liquids like polychlorinated biphenyls may combine good insulatingproperties, i.e. a high dielectric strength, with good coolingproperties. However, these liquids may be toxic. A transformer chamberwith a liquid-tight tank may thus prevent that persons are exposed tothese toxic substances.

Transformer oil has also been found to combine good cooling propertiesand insulating properties. However, transformer oil may be lessfire-resistant. The liquid-tight tank may prevent that leakingtransformer oil reaches surfaces having a temperature above a flamepoint of the transformer oil. Hence, a transformer chamber with aliquid-tight tank may prevent inflammation of the transformer oil.

The transformer chamber may comprise a pit, in particular an oil pit.The pit may allow collecting liquid, in particular transformer oil,during transformer chamber maintenance and reduce the amount of, e.g.toxic or burnable, substances within the transformer chamber.

According to an embodiment of the transformer chamber for a windturbine, the transformer chamber comprises a liquid-filled transformerwith low voltage terminals and high voltage terminals, wherein the lowvoltage terminals and high voltage terminals are accessible from a topsurface of the transformer chamber.

This may reduce the time necessary for electrical installation of thetransformer while at the same time maintaining the structural integrityof the liquid-tight tank. In particular, the transformer chamber mayremain an essentially sealed tank such that no liquids may leak throughthe transformer chamber.

According to another embodiment of the transformer chamber for a windturbine, the transformer chamber comprises a damper, in particular adamper including hydraulic cylinders. Typically, transformers have aquite high mass, because they are essentially composed of huge amountsof copper and iron. Providing the transformer chamber for a wind turbinewith a damper may reduce the oscillations associated with thetransformer being arranged in at the top of a wind turbine. Thus, theload on the wind turbine tower may be reduced.

According to yet another embodiment of the transformer chamber for awind turbine, the liquid-tight tank is an explosion safe tank comprisingan explosion plate, in particular an explosion plate made from aluminum.

Gas may be produced during operation of the transformer, which gas mayexplode. If the liquid-tight tank is constructed so as to be anexplosion safe tank comprising an explosion plate the risk to damageelements near the transformer in case of a transformer explosion may belimited.

The explosion plate of the explosion tank may work as a predeterminedbreaking point. Thus, pressure due to the explosion may be released in adetermined way.

Aluminum may be in particular suitable because of its lower strengthcompared to steel, which may be the preferred material for thetransformer chamber.

According to a still further embodiment of the transformer chamber for awind turbine, the transformer chamber comprises guiding elements, inparticular wheels.

These guiding elements may facilitate installation of the transformerchamber. Typically, the transformer chamber is installed at the top ofthe wind turbine, e.g. in the wind turbine nacelle or the wind turbinetower. The guiding elements, in particular wheels, may allow supportingthe transformer chamber against the wind turbine tower either from theoutside or form the inside when it is winched to the top. Theexchangeability of the transformer chamber may likewise be improved.

According to a second aspect there is provided a wind turbine structurecomponent comprising a component bedframe adapted for receiving atransformer chamber. The component bedframe may allow a particularlyeasy fixing of the transformer chamber to the wind turbine structurecomponent.

According to a first embodiment of the wind turbine structure component,the wind turbine structure component comprises a cooling channel system.

During operation heat has to be dissipated from the liquid-filledtransformer. Providing the transformer chamber with a cooling channelsystem may allow for heat dissipation by convection that may be moreefficient than heat dissipation by radiation and/or conduction. Inparticular, the cooling channels may be construed to guide air throughfins of the liquid-filled transformer. Fins may augment the effectivesurface for heat dissipation.

According to second embodiment the wind turbine structure componentcomprises a damper, in particular a hydraulic cylinder damper.

Typically, transformers have a quite high mass, because they areessentially composed of huge amounts of copper and iron. Providing thewind turbine structure component with a damper may reduce theoscillations associated with the transformer being provided at the topof a wind turbine. Thus, the load on the wind turbine tower may bereduced.

According to another embodiment of the wind turbine structure componentis a wind turbine tower segment.

If the wind turbine structure component is a wind turbine tower segment,the transformer chamber may be guided within the wind turbine towerduring installation. Thus, installation of the transformer chamber maybe performed in an environment protected from wind and rain.Furthermore, the transformer chamber may not be subjected to rotationalforces when the wind turbine rotor is moved into the wind direction.

According to a yet another embodiment of the wind turbine structurecomponent is a wind turbine nacelle.

The weight of the transformer may be beneficial when the wind turbinenacelle is adapted to receive the transformer chamber. The transformermay in this way be a counterweight to the wind turbine rotor.

Placing the transformer chamber at the top of the wind turbine may helpto reduce the cable length from the generator or converter to thetransformer, in particular when the transformer chamber is providedwithin the wind turbine nacelle.

According to a further embodiment the wind turbine structure componentcomprises a winch.

The winch may render allow for installation of the wind turbine chamberwithout providing a crane. Thus, installation of the wind turbinechamber may be cheaper, in particular for offshore wind turbines. Allmeans to install the transformer chamber may be provided on site.

According to a still further embodiment the wind turbine structurecomponent comprises a hatch. The hatch may allow moving the transformerchamber into the wind turbine structure

According to another embodiment the wind turbine structure componentcomprises at least one cooling air inlet and at least one cooling airoutlet adapted to provide the transformer chamber with cooling air.

During operation heat has to be dissipated from the liquid-filledtransformer and the transformer chamber. Providing the transformerchamber with at least one cooling air inlet and at least one cooling airoutlet adapted to provide the transformer chamber with cooling air mayallow using the wind driving the wind turbine rotor to be used forcooling.

According to yet another embodiment the wind turbine structure componentcomprises a fan. A fan may augment the amount of air provided to thetransformer chamber and/or other components of the wind turbine. Thus,even when there is a minimal wind, overheating of wind turbinecomponents may be avoided.

According to a third aspect there is provided a wind turbine comprisinga transformer chamber as has been described hereinbefore and a windturbine structure component, wherein the transformer chamber isdetachably connected to the component bedframe.

Such a wind turbine allows easy exchangeability of the transformerchamber and the transformer in case of a transformer failure.Furthermore, installation of the wind turbine, in particular at offshorelocation, may be simplified.

According to an embodiment of the wind turbine the transformer chamberis movable, in particular in the direction of gravity, relative to thewind turbine structure component.

Such a wind turbine may further facilitate the installation of thetransformer chamber within the wind turbine structure component. A windturbine nacelle may, for example, be provided with a hatch at the bottomsuch that the transformer chamber may be winched through the openedhatched.

According to a forth aspect there is provided a method for assembling awind turbine as has been described hereinbefore.

The method may in particular be useful to erect and to overhaul a windturbine.

It has to be noted that embodiments have been described with referenceto different subject matters. In particular, some embodiments have beendescribed with reference to method type claims whereas other embodimentshave been described with reference to apparatus type claims. However, aperson skilled in the art will gather from the above and the followingdescription that, unless other notified, in addition to any combinationof features belonging to one type of subject matter also any combinationbetween features relating to different subject matters, in particularbetween features of the method type claims and features of the apparatustype claims is considered as to be disclosed with this document.

The aspects defined above and further aspects are apparent from theexamples of embodiment to be described hereinafter and are explainedwith reference to the examples of embodiment. The embodiments will bedescribed are in more detail hereinafter and are meant to beillustrative and not limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a transformer chamber in a perspective view.

FIG. 2 shows a cutaway view of a transformer chamber.

FIG. 3 shows another cutaway view of a transformer chamber.

FIG. 4 shows yet another cutaway view of a transformer chamber.

FIG. 5 shows a further cutaway view of a transformer chamber.

FIG. 6 shows a still further cutaway view of a transformer chamber.

FIG. 7 shows a cooling channel system of a transformer chamber.

FIG. 8 shows a section of a wind turbine.

FIG. 9 depicts a wind turbine nacelle.

FIG. 10 shows a section of a wind turbine nacelle.

FIG. 11 depicts a section of a wind turbine nacelle.

FIG. 12 shows a transformer chamber

FIG. 13 shows a transformer chamber

FIG. 14 shows a section of a wind turbine nacelle.

DETAILED DESCRIPTION OF INVENTION

The illustration in the drawing is schematically.

FIG. 1 shows a transformer chamber 1 with an explosion safe tank 2 in aperspective view. The transformer chamber 1 surrounds an oil-filledtransformer 3 only the top of which is visible. Air may flow through afirst opening 4 into a cooling channel system of the transformer chamber1, where it may absorb heat generated by the oil-filled transformer 3.The hot air may then leave the cooling channel system of the transformerchamber 1 through a second opening 5.

The bottom section of the transformer chamber 1 up to the height of thefirst opening 4 may be formed as an oil pit 6. Leaking oil from adamaged oil-filled transformer, e.g. after an explosion of theoil-filled transformer, may be collected within the oil pit 6. Anexplosion plate 7 made of aluminum may work as a predetermined breakingpoint and may reduce the damages in case of an explosion of theoil-filled transformer 3.

An upper side of the transformer chamber 1 is open and allows easyaccess to a high voltage terminal 8 and a low voltage terminal 9 of theoil-filled transformer 3. This may allow a quick and easy replacementand reconnection of the oil-filled transformer 3 to electric wires. Thetop of the oil-filled transformer 3 further comprises transport rings10, 11, to which a hook or chain can be attached when an exchange of theoil-filled transformer 3 becomes necessary and the transformer chamber 1with the oil-filled transformer therein needs to be lowered to or pickedfrom surface level with a winch.

The transformer chamber 1 further comprises two support rails 12, 13,which may be used to attach the transformer chamber 1 to a bedframe of,e.g. a wind turbine nacelle. Two support beams 14 and 15 may enhance therigidity of the transformer chamber 1.

FIG. 2 shows a cutaway view of a transformer chamber 16 with anexplosion safe tank 17. Like the transformer chamber 1 shown in FIG. 1the transformer chamber 16 comprises an oil-filled transformer 18, afirst opening 19, a second opening 20, an oil pit 21, an explosion plate22, a high voltage terminal 23, a low voltage terminal 24, transportrings 25, 26, support rails 27, 28, and support beams 29, 30. Thefeatures of this embodiment have been described with reference toFIG. 1. The oil-filled transformer 18 is placed in the transformerchamber 16 such that the distance between cooling fins 31 of theoil-filled transformer 18 and the wall of the transformer chamber 16 iskept very narrow. The narrow arrangement forces the air coming from thefirst opening along the cooling fins 31 for better cooling of thesurfaces of the oil-filled transformer 18.

FIGS. 3, 4, 5 show further cutaway views of transformer chambers 32, 45,58 with an explosion safe tank 33, 46, 59. These transformer chambers32, 45, 58 also include an oil-filled transformer 34, 47 a firstopening, a second opening 35, 48 an oil pit, an explosion plate, a highvoltage terminal 36, 49, 60 a low voltage terminal 37, 50, 61 transportrings 38, 39, 51, 52, 62, 63 support rails 40, 41, 53, 54, 64, 65,support beams 42, 43, 55, 56, 66, 67, and cooling fins 44, 57 comparableto those as have been described hereinbefore.

FIG. 6 shows a still further cutaway view of a transformer chamber 68focusing on its explosion plate 69 above its first opening 70. Theexplosion plate 69 is made from aluminum and represents a predeterminedbreaking point, which bursts in case of an explosion and allows releaseof pressure at a secure location avoiding unpredictable and harmfuldamage to the transformer chamber 68 and its features. The explosionplate is fixed to the transformer chamber 68 with seven bolts 71, 72,73, 74, 75, 76, 77 of which five bolts 71, 72, 73, 74, 75 are locatedalong a bottom portion parallel to the first opening 70. A bendingsection of the explosion plate is created with slits 78 running parallelto the first opening 70. Two deformation bolts 76, 77 hold the explosionplate 69 to the transformer chamber 68 on an upper section of theexplosion plate 69. In case of an explosion these two bolts 76, 77 andthe explosion plate 69 bends outwardly along the bending section. Thebending section works similar to a hinge.

FIG. 7 shows a cooling channel system 79 for a transformer chamber. Twoinlet interfaces 80, 81 may be connected to transformer chamber's firstopenings. One outlet interface 82 may be joinable to a second opening ofa transformer chamber. A fan may be located behind the outlet interfaceand create a cooling airflow by sucking in ambient air. This air maythen be fed into the transformer chamber through the two inletinterfaces 80, 81 and be received by the outlet interface 82 before itis blown out through the channel outlet 83 of the cooling channel system79.

FIG. 8 shows a section of a wind turbine 84 comprising a wind turbinetower 85. A person 86 is depicted to give an indication of the size ofthe wind turbine 84. A wind turbine nacelle 87 is mounted to the top ofthe wind turbine tower 85. The outer walls of the wind turbine nacelle87 are not shown. The wind turbine nacelle 87 comprises a supportstructure and a component bedframe 88, which is bolted to the supportstructure. However, the component bedframe 88 and the support structuremay in an alternative embodiment also be made in one piece.

The support structure is rotatable connected to the wind turbine tower85 and supports a generator 89 with a wind turbine rotor 90 connectedthereto. The wind turbine rotor 90 comprises a hub 91 and blades 92.

The component bedframe 88 and the support structure carry inter aliaelectrical components 93 such as a converter, communication units andcontrol units. A transformer chamber 94 holding an oil-filledtransformer is mounted to the bottom side of the component bedframe 88in close vicinity to the wind turbine tower 85. The center of mass islocated close to the wind turbine tower 85 by positioning the heavyoil-filled transformer close to the wind turbine tower 85. Thus,structural loads on the wind turbine 84, in particular on the windturbine tower 85, the support structure and the component bedframe 88,may be minimized.

Furthermore, by placing the transformer chamber 94 on the opposite sideof the wind turbine rotor 90 the weight of the transformer chamber 94comprising the oil-filled transformer may counteract the weight of thewind turbine rotor 90. This may additionally reduce structural loads.

The transformer chamber 94 comprises guiding in elements in form ofwheels. These wheels may allow an easy movement of the transformerchamber 94 relative to the wind turbine tower 85, which may be used asguidance when the transformer chamber 94 is lowered to the surface orraised therefrom. Guiding the transformer chamber 94 may reduce thesecurity risks associated with swinging masses.

The wind turbine nacelle 87 may additionally comprise a winch with achain or rope, which is attachable to the transformer chamber 94. Thismay allow exchanging the transformer chamber 94 without the need ofadditional cranes.

FIG. 9 depicts a wind turbine nacelle 95 mounted to the top of a windturbine tower 96. A transformer chamber 97 comprising an explosion safetank 98 is bolted to a component bedframe 99. A ladder 100 provides easeof access to the transformer chamber 97 and to electrical components 101from the support structure. The ladder 100 and the placement of thetransformer chamber 97 with the transformer therein inside the canopy ofthe wind turbine nacelle 95 may allow repair work and service to be doneeven under adverse weather conditions.

FIG. 10 shows a section of a wind turbine nacelle 102 in a cutaway view.The wind turbine nacelle 102 houses a transformer chamber 103 with anexplosion safe tank. The transformer chamber 103 comprises an oil-filledtransformer 104 and is attached to a component bedframe of the windturbine nacelle 102. A hatch 105 is provided such that the transformerchamber 103 may easily be lowered from the wind turbine nacelle 102 tothe surface. The wind turbine nacelle 102 further houses electriccomponents 106, e.g. a converter, communication units and control units,which may be arranged in cabinets on a support structure of the windturbine nacelle 102. The access to the transformer chamber 103 and tothe electric components 106 may be facilitated by means of a ladder 107.The wind turbine nacelle 102 further comprises a cooling channel system108 for the transformer chamber 103. Fans 109 blow ambient air into thecooling channel system 108 and the transformer chamber 103, where itserves to dissipate from the oil-filled transformer 104. The hot airthen is guided by the cooling channel system 108 to the channel outlet110 where it is released to the outside of the wind turbine nacelle 102.

FIG. 11 depicts a section of a wind turbine nacelle 111 housing atransformer chamber 112. Only parts of the transformer chamber 112 areshown. A transformer (not shown) rests on two pads 113, 114 of thetransformer chamber 112. The pads 113, 114 may be made of a resilientmaterial and absorb the vibrations associated with the frequency of thepower grid. The material may in particular be adapted to absorbvibrations with a frequency of 50 Hertz or 60 Hertz. A support beam 115is provided to augment the rigidity of the transformer chamber 112. Thetransformer chamber 112 is attached to the component bedframe of thewind turbine nacelle 111 with two support rails 116, 117 such that incase of an explosion of the transformer an explosion plate 118 of thetransformer chamber 112 may work as a predetermined breaking point andthe pressure may be released in a direction laterally of the windturbine nacelle 111. Thus, harmful damages to other components withinthe wind turbine nacelle 111 may be avoided or at least reduced. A windturbine tower 119 supports the wind turbine nacelle 111 and a cable 120transmits the power generated from a high voltage terminal of theoil-filled transformer along the inside of the wind turbine tower 119 tothe main power grid.

FIGS. 12 and 13 show a transformer chamber 120. The transformer chamber120, 128 comprises L-shaped support rails 121, 122, 129. With theseL-shaped support rails 121, 122, 129 the transformer chamber 120, 128 isbolted at four corners 123, 124, 125 to a component bedframe 126 of awind turbine nacelle 127. The transformer 130 is bolted to the top 131and the bottom 132 of the transformer chamber 128.

FIG. 14 shows a section of a wind turbine nacelle 133 at the top of awind turbine tower 134. The wind turbine nacelle 133 comprises an inlet135 for sucking in ambient air for cooling of components within the windturbine nacelle 133 and an outlet 136 for blowing out hot air.

While specific embodiments have been described in detail, those withordinary skill in the art will appreciate that various modifications andalternative to those details could be developed in light of the overallteachings of the disclosure. For example, elements described inassociation with different embodiments may be combined. Accordingly, theparticular arrangements disclosed are meant to be illustrative only andshould not be construed as limiting the scope of the claims ordisclosure, which are to be given the full breadth of the appendedclaims, and any and all equivalents thereof. It should be noted that theterm “comprising” does not exclude other elements or steps and the useof articles “a” or “an” does not exclude a plurality.

1. A wind turbine, comprising: a transformer chamber for a wind turbine,comprising a liquid-tight tank for receiving an oil-filled transformer,a nacelle comprising a component bedframe adapted for receiving atransformer chamber; and a rotor, wherein the transformer chamber isdetachably connected to the component bedframe, and wherein thetransformer chamber is placed on the opposite side of the rotor.
 2. Thewind turbine according to claim 1, further comprising: low voltageterminals; and high voltage terminals, wherein the low voltage terminalsand high voltage terminals being accessible from a top surface of thetransformer chamber.
 3. The wind turbine according to claim 1, furthercomprising: a damper including hydraulic cylinders.
 4. The a windturbine according to claim 1, wherein the oil-tight tank is an explosionsafe tank and comprises an explosion plate.
 5. The a wind turbineaccording to claim 4, wherein the explosion plate is made from aluminum.6. The wind turbine according to claim 1, further comprising: comprisingguiding elements.
 7. wind turbine according to claim 6, wherein theguiding elements are wheels.
 8. The wind turbine according to claim 1,further comprising: a cooling channel system.
 9. The wind turbineaccording to claim 1, wherein the component bedframe comprises a damper.10. The wind turbine according to claim 1, wherein the damper is ahydraulic cylinder damper.
 11. The wind turbine according to claim 1,further comprising: a winch and/or a hatch.
 12. The wind turbinestructure component according to claim 1, further comprising: a coolingair inlet and a cooling air outlet adapted to provide a cooling air pathin the transformer chamber.
 13. The wind turbine structure componentaccording to claim 12, further comprising: a fan.
 14. The wind turbineaccording to claim 1, wherein the transformer chamber is movablerelative to the wind turbine structure component.
 15. The wind turbineaccording to claim 1, wherein the transformer chamber is movable thedirection of gravity.
 16. A method for assembling a wind turbineaccording to claim 1.